So after my review and experience with the Resonessence Labs Herus portable headphone amplifier and DAC, I was very excited to give the Concero HP an audition. It is quite a bit bigger than the Herus (but then again, that’s not hard) and is more on par with the size of my 1Gb back-up Western Digital USB hard drive. Unlike the Herus, the Concero HP does have a volume control knob which definitely is a welcomed addition in my opinion. The Concero HP fully supports up to a whopping 352.8 kS/s bit rate. It deploys the very well respected ESS9018 Sabre DAC chip and unlike several other DACs that I’ve heard/owned with this chipset, it doesn’t suffer from the drawbacks I’ve found.
Resonessence Labs, while a relatively new company to this industry, has put out quite the plethora of products; ranging from their entry level Herus right up to their top of the line Mirus and Invicta DACs. Located in beautiful British Columbia, Canada, I am very happy to see a Canadian company come to the forefront of producing some truly outstanding products. The Concero HP is similar to the Concero DAC, but instead of analog RCA outputs, the unit was designed to drive headphones directly as it has an internal headphone amplifier. While the Herus could run out of steam with more demanding headphones like the Sennheiser HD800s or Audeze LCD-X (though it certainly did an admirable job as a portable unit), thankfully the Concero HP has really stepped up to the plate with regards to the extra power. The Herus could output 19mW into the 300 ohm HD800s and could play them to sound quite pleasantly (though never very loud); the Concero HP can output approximately 207mW into the same load and the extra head-room was certainly apparent upon my first listen. The dynamics and control of the drivers were very quickly discernible and while more expensive ($850 for the Concero HP vs. $350 for the Herus) the value of this product was easily justified to my ears if looking to drive these more power hungry full sized headphones.
The inputs of the Concero HP are either USB (through your PC or Mac) or SPDIF (CD player/transport) and there is a single headphone output. There is an option to change the SPDIF input into an output and thus make the Concero a USB to SPDIF converter. However for the purposes of this review, I did not use this functionality. I do however wish that Resonessence Labs also included a set of RCA (un-balanced) outputs to feed a separate headphone amplifier and thus make this unit more flexible and give the owner more options. As an added bonus, the Concero HP is compatible with the Apple TV remote…and I can confirm using the pair was simple to setup and came in quite handy.
Overall; while just slightly bigger than my backup Seagate 1Tb hard drive, the Concero HP is quite the looker. “CONCERO” is embossed along the top and the volume knob serves to control the volume of the music and switch between oversampling filters (if depressed). For those of you looking for an all-purpose amplifier/DAC that looks sleek and you have very limited desk space, the Concero HP is a wonderful all-in-one solution (assuming it’s within your budget of course). Just plug in the USB (supports USB 2.0) into your PC or Mac, select your oversampling filter and sit back and enjoy the tunes.
My first test track is an old standard for me. Pink Floyd’s “Dark Side of the Moon” ranks as one of my all-time favourite albums. For this particular review, I selected both the most recent 2011 Immersion Edition (mixed by James Guthrie) and the 30th Anniversary SACD (mixed by Alan Parsons). My full sized headphones for this album were the recently updated flagship Grado PS1000e. As soon as the heartbeats started to play and reverberate, I could tell that the Concero HP could extract even the tiniest nuances from the recording. I was floored just how well this little amp/DAC could pull minute details from this album. I quickly turned on my main headphone setup (HeadAmp GS-X Mk2 + Metrum Acoustics Hex) and did some A-B comparisons. I was shocked just how well the Concero HP could keep up with my much larger and much more expensive main headphone rig. Now, the GS-X Mk2 / Hex combination is likely the best I’ve heard the PS1000e’s sound, but considering the difference in price (by a factor of more than 7.5X) and form factor (likely more than a factor of 12X), the Concero HP was not put to shame by any means. I was able to listen to my main rig and then switch over to the Concero HP and still be totally satisfied with the experience. That for me says a lot about the value proposition of this little wonder. The other thing that struck me after a few songs in, was the sound signature. It was a bit different from most other Sabre based products I’ve experienced through the years…but all in a good way.
While a very advanced chipset, I’ve found that sometimes Sabre based DACs tend to suffer from “digititus”; a sound signature that can be overly analytical, on the brighter side of neutral and thus (at times) lack a natural flow of the music. Very quickly I was able to surmise that the Concero HP didn’t suffer from these drawbacks. And this is with direct A-B comparisons to the Non-Oversampling Hex DAC that is renowned for overcoming these digital characteristics. As well, the “Sabre-shout” (as I put it) of the upper midrange/lower treble that afflicted some of my previous Sabre based DACs was completely gone with the Concero HP. The folks at Resonessence Labs were able to pull all the fantastic capabilities of the ESS-9018 chipset and apply an analog section that offered a very natural and pleasing presentation. Talk about having your cake and eating it too! The bass had wonderful weight to it and even the smallest details were readily apparent. The bloom was a bit more than what I was used to, but certainly it didn’t take away from my enjoyment. It was still deep, fast and detailed. The sound staging of Money was breath taking. The Grado PS1000e’s offer some of the best ability to image a recording this side of the “king of the hill” Sennheiser HD800s and when paired with the Concero HP, that image was both widened and deepened. Instrumental separation was top notch. Every player and instrument was clearly presented and there was never any instance when I thought there was any blurring. Vocals and treble were equally outstanding. Grado headphones tend to fall on the brighter side of neutral; however, I was thoroughly impressed with the pairing with the Concero HP. I never found myself reaching to turn down the volume dial to account for an overabundance of overly zealous treble on a recording. The music flowed quite naturally from the PS1000e/Concero HP that I was saddened when all 42 minutes and 59 seconds of the album were over.
Next up was Wycliffe Gordon’s “Dreams of New Orleans“. This is a wonderful high resolution binaural recording. And the Concero HP managed to keep up with this very demanding recording. This time, my headphones were the Fostex TH-900s. These are wonderfully quick sounding closed headphones that can sound more “open” than most open headphones. The tone and timbre of the brass instruments in particular was as true to life as I’ve come across with this pairing. The sound-staging was simply amazing, it was as if I was there in the club with Wycliffe and his band. Each instrument was clearly and accurately portrayed. Instrumental separation again was very concise and clear. Being a long time brass player (trumpet) I am usually very critical of how these instruments are rendered. I am very happy to say that the Concero HP passed with flying colours. Trumpets were vibrant and alive, trombones were deep and quick and overall I was left with a very satisfied feeling. I hate to go back to the size of the HP, but I am amazed just how great this little wonder performs; it really left me rethinking some of my prejudices with regards to audio gear and their correlation sound quality to size and weight. That is simply not true anymore as it appears that the technology deployed by Resonessence Labs has really made this no longer a requirement.
As soon as I put in Kat Edmonson’s “Way Down Low” I knew that the Concero HP did a very admirable job with my harder to drive Sennheiser HD800s. I’ve found through the years that the HD800s are among the hardest headphones to “get right” with upstream gear. They are incredibly transparent and let you hear what’s coming through your source material, DAC and amplifier. First off, the HD800s are 300 ohm headphones with an efficiency of 102dB. That’s certainly not in the realm of the very hard to drive HifiMan HE-6s (with an efficiency of only 83.5dB), but I’ve found them a bit of a challenge for most smaller sized amplifiers. Now right off the bat, the HD800s sounded rich and inviting when listening to this recording. However, the differences between my much larger HeadAmp GS-X Mk2 / Metrum Accoustics Hex were more apparent. I think the extra power provided by the GS-X Mk2 went a long way in getting a firmer control of the HD800’s drivers. So while not the be all and end all HD800 solutions, the Concero HP offered a very pleasing and enjoyable experience. The volume could only get to a medium loud level, but as I listen to music at safe levels (74dB ish with 85dB peaks), I found the Concero HP more than up to the task. Kat’s voice was simply outstandingly clear, the vibrato was eerily life-like. I was more than happy to confirm that the Concero HP when driving the HD800s produced wonderfully rich female vocals. Unfortunately I’ve had less than stellar experiences with the HD800s with upfront amplifiers or DACs that were unnatural sounding. The HD800s only served to relay that unnaturalness through. I suppose that is the curse with transparent headphones as these, but thankfully what I heard was more than enough to recommend the Concero HP for those looking for a mid-level performer that will make them sound great (though not at their apex) and all in a convenient size factor for when desktop space is limited. I find this unit perfect for my office at work where I have very limited space and don’t want a large sized (or even mid-sized) amplifier or DAC visible.
I found the sonic improvements over the already great sounding Herus quite astonishing. The improved mids and treble and sound staging on the Concero HP really put it over the top for me. Although it can’t be used as a portable amp/DAC like the Herus can with iDevices or Android devices, it is a worthwhile all-in one desktop solution that is worthy of it’s price tag. It offers seriously good audiophile level enjoyment in a small package and drove everything that I threw at it; from my Shure SE35 IEMs right up to my full
sized Audeze LCD-X orthodynamic headphones. I was also a bit surprised how well my Sennheiser HD800s sounded through this little unit too. As mentioned, I find getting these headphones to sound their best is not a task for the weary of faint of heart. But with the Concero HP, I found myself quite satisfied. Although not a “final” solution for these headphones, I can definitely enjoy this combination for extended sessions. Something I can’t say about most upstream amplifiers/DACs that I’ve tried with the HD800s (and many cost quite a bit more and took up even more valuable desktop space).
So in the end, I am giving the Resonnessence Labs Concero HP two big thumbs up! I think they have passed my final test; the “Put Your Money Where Your Mouth Is” test and I did purchase the review sample. I found that it is the perfect workplace setup for me. It takes up very little room and can drive all of my headphones and IEMs and make them all sound incredibly enjoyable. If you’re in the market for an all-in one amplifier/DAC solution and don’t have a lot of space I would seriously recommend giving the Concero HP and audition and remember: great things sometimes do come in small packages!
By day, I’m a husband, father and professional engineer. But by night, I’m an audiophile and music junkie. Many say that music is food for the soul and nothing works better for me than Led Zeppelin, The Beatles, The Rolling Stones, Rush and Miles Davis. For the past 25 years I’ve been on an audio journey that continues to this day.